CH662355A5 - COPOLYMER RESIN AND LENSES IN PLASTIC MADE OF THIS COPOLYMER RESIN. - Google Patents

Description

The invention relates to a copolymer resin and lenses made of plastic, which is derived from this copolymer resin.

Plastic lenses have found increasing commercial use as eyeglass lenses, camera lenses, and other optical lenses in recent years because they are lighter, less fragile, and easier to color compared to inorganic glass lenses. As the resin which is known to be used in large quantities for this use, there is a resin obtained by cast polymerization of diethylene glycol bisallyl carbonate, hereinafter referred to as CR-39. However, the refractive index nd of this resin is 1.50, which is small compared to the refractive index of inorganic glass lenses (nd = about 1.52). In order to achieve the same optical properties as with glass lenses, it is necessary to

ke in the center, increasing the thickness at the edge and the curvature of the plastic lens, which inevitably makes the plastic lens thicker as a whole. For this reason, there is a great need for the development of a resin for manufacturing lenses that has an even higher refractive index. Polycarbonate (nd = 1.58-1.59), polystyrene (nd = 1.58-1.60), etc. were already known as resins with a high refractive index 55. Each of these resins is a thermoplastic polymer with a two-dimensional structure. They are therefore unsuitable for the process of casting polymerization, which is suitable for the production of objects of various shapes such as for the production of spectacle lenses, and their processing after casting, in particular their raw and fine grinding (hereinafter referred to as grinding) difficult. Therefore, the use of these resins is currently limited to certain types of safety glasses and the like. limited.

Accordingly, there is a great need for the development of a resin for manufacturing lenses that has a refractive index that is higher than that of the Har

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zes for the production of lenses, which is obtained by polymerizing CR-39, but, like CR-39, can be exposed to casting polymer and, thanks to its three-dimensional cross-linking structure, does not clog diamond-loaded grindstones when grinding cast lens blanks. A variety of researches have been undertaken to develop a resin which would satisfy the above-mentioned desire, and as a result, resins have been proposed which have been obtained by copolymerization of CR-39 and second monomers which have been applied to the homopolymers in question Measurement have higher refractive indices than those of CR-39 (see Japanese Patent Laid-Open Nos. 79 353/1979, 7787/1978, 15, 118/1980 and 36 601/1981). However, the refractive indices of the resins thus copolymerized are inherently limited because they use CR-39 as the main component. It was therefore difficult to obtain a resin with a high refractive index, for example with a refractive index of 1.55 or higher.

In order to obtain a resin which has an even higher refractive index, it is imperative to use a bifunctional monomer which can give a homopolymer with a refractive index which is higher than that of CR-39. However, each of the bifunctional monomers previously proposed resulted in a polymer whose impact resistance was much inferior to that of the CR-39 polymerized homopolymer alone. Thus, some attempts have been made to improve the impact resistance of these bifunctional monomers by copolymerization with a unifunctional monomer. Here it is necessary that any suitable unifunctional monomer have a high refractive index when measured on the homopolymer in question, if it is desired to obtain a copolymer of high refractive index. For this reason, styrene or a halogen substituted styrene is currently used as such a unifunctional monomer. However, the hitherto proposed use of bifunctional monomers other than CR-39 in combination with the above-mentioned unifunctional monomers is accompanied by such disadvantages as the generation of deformation during the polymerization, and it is difficult to obtain polymers which have a uniform distribution of the refractive index because there are large differences in the polymerization reactivity between such bifunctional and monofunctional monomers and the proportions between the bifunctional and monofunctional monomers cannot be varied arbitrarily because of their poor mutual miscibility.

In view of the foregoing, the inventors have conducted extensive research to overcome the 5 disadvantages mentioned above through improvements. As a result, it was found that a resin which has a high refractive index is easy to process and grind, for example, and has excellent miscibility between the unifunctional and io bifunctional starting monomer when copolymerized, develops less deformation during the polymerization, and it is therefore suitable to be used for the production of high refractive index lenses that it can fall into radical polymerization by copolymerizing a specific bi-i5 functional monomer with a unifunctional monomer which has a refractive index of at least 1.55 as a homopolymer and contains an aromatic ring, which the present invention has accomplished. 20 The present invention thus provides a copolymer resin containing structural units of the general formula (III)

N! ✓

35 in which X is a hydrogen, chlorine or bromine atom and R is a hydrogen atom or a methyl group, and (IV)

45

wherein R 'represents a hydrogen atom or a methyl group and Y

° // ~ X ^ "

-oc - </ ^. -ch2oc- (Q) ^ (^)

o is o, where X 'is a chlorine or bromine atom, q is an integer in which X is a hydrogen, chlorine or bromine atom

Value from 0 to 5 and r is 0 or 1. This resin is and R is a hydrogen atom or a methyl group obtained by polymerizing at least one carbo- or at least one unifunctional monomer of the general

nate compound of the general formula I and formula II

R '

x or i

II I- m C = CH2 (II)

ch2 = c-ch2oco-> -ococh2c = ch2 (1) i

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where R 'represents a hydrogen atom or a methyl group and Y

-ch2oc-

■ (O).

-c-q-

H

-co-ch-II 2 0

ß ') q ode-r

H

H

where X 'is a chlorine or bromine atom, q is an integer from 0 to 5 and r is 0 or 1.

The invention also provides a plastic lens whose plastic is derived from the aforementioned copolymer resin. The first monomer according to the invention, namely the carbonate compound of the general formula (I), can be obtained by a carbonation reaction, namely via the dehydrochlorination between bisphenol A (4,4'-isopropylidenediphenol) or its halo on the ring Generated compounds and allyl chloroformate or methallyl chloroformate. The following compounds can be mentioned as specific examples of the carbonate compound of the general formula (I):

4,4'-isopropylidenediphenylbisallyl carbonate 4,4'-isopropylidenediphenylbis-ß-methallyl carbonate 4,4'-isopropylidene-2,2 '<5,6'-tetrachlorodiphenylbisallylcarbonate

4,4'-isopropylidene-2,2 ', 6,6'-tetrachlorodiphenylbis-ß-methallyl carbonate

4,4'-isopropylidene-2,2 ', 6,6'-tetrabromodiphenylbisallyl carbonate

4,4'-isopropylidene-2,2 ', 6,6'-tetrabromodiphenylbis-ß-methallyl carbonate

The carbonate of the general formula (I) is copolymerized, using a unifunctional monomer of high refractive index in the homopolymer state as the second monomer because the impact resistance of a polymer obtained by polymerizing the ester alone is far too low.

In particular, the second monomer according to the invention is a unifunctional monomer of the general formula (II) with a refractive index of at least 1.55 in the homopolymer state, capable of entering into radical polymerization and containing an aromatic ring. This monomer has good miscibility with the carbonate of the general formula (I) and is able to maintain good homogeneity in the liquid state when it is poured into molds for polymerization. The following may be mentioned as typical examples of such monomers: vinyl, isopropenyl, allyl or β-methallyl esters of benzene acid or benzene acids halogenated on the ring: for example (vinyl, isopropenyl, allyl or β-methallyl) benzoate , -2-chlorobenzoate, -3-chlorobenzoate, -4-chloro-benzoate, -2,4-dichlorobenzoate, -2,5-dichlorobenzoate, -2,6-di-chlorobenzoate, -3,4-dichlorobenzoate, -3 , 5-dichlorobenzoate, -2,3,6-trichlorobenzoate, pentachlorobenzoate, -2-bromobenzoate and -3-bromobenzoate.

(Allyl or ß-methallyl) carbonates, acrylates or methacrylates of phenol, phenols halogenated on the ring, benzyl alcohol or benzyl alcohols halogenated on the ring: for example (allyl or ß-methallyl) carbonates, -acrylates, or -methacrylates of phenol, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, 2,3-dichlorophenol, 2,4-dichlorophenol, 2,5-dichlorophenol, 2,6-dichlorophenol, 3 , 4-dichlorophenol, 2,4,5-trichlorophenol, 2,3,4,6-te-trachlorophenol, pentachlorophenol, 2-bromophenol,

3-bromophenol, 4-bromophenol, 2,4-dibromophenol, 2,4,6-tribromophenol, pentabromophenol, benzyl alcohol, 2-chlorobenzyl alcohol, 2,4-dichlorobenzyl alcohol and 2-bromobenzyl alcohol.

s styrene, chlorinated styrenes on the ring or brominated styrenes on the ring.

Preferably, the carbonates of the general; Formula (I) which uses vinyl, allyl or β-methallyl esters of ben-io zoic acid or benzoic acids halogenated on the ring, or the allyl or β-methallyl carbonates of phenol or phenols halogenated on the ring.

In the present invention, the proportion of each carbonate represented by the general formula (I) cannot be limited to a certain value or range because the preferred proportion may vary depending on the kind of the carbonate. However, the carbonate of the general formula (I) can be used in a proportion of 20 to 80% by weight or preferably 30 to 70% by weight. 20 When the carbonate is added in a proportion lower than 20% by weight, the resulting copolymerized resin has a very low surface hardness. Proportions greater than 80% by weight are not preferred because the impact resistance is reduced. According to Dement-25, it is preferred to use one or more of the monomers of the general formula (II) described above and to copolymerize them in a proportion of 20 to 80% by weight of the carbonate of the general formula (I).

In addition, no particular restriction is imposed on the type of initiator of radical polymerization which is to be used when carrying out the copolymerization to obtain a resin according to the invention for the production of lenses. It is preferred to use a known peroxide, such as benzoyl peroxide, p-chlorobenzoyl peroxide, lauroyl peroxide, diisopropyl peroxy carbonate, di-2-ethylhexyl peroxy carbonate or tert-butyl peroxypivalate or a known one, in a proportion of 0.01 to 5% by weight Azo compound such as azobisisobutyronitrile. The resin for the production of lenses according to the invention can be obtained by carrying out the known cast polymerisation process with a mixture of at least one carbonate of the general formula (I), at least one second monomer of the general formula (II) described above and an initiator of radical polymerisation in other words, by pouring the mixture into a mold, which is formed by a seal or a spacer and a mold made of glass or metal, and then polymerizing and curing 50 the mixture by heating to temperatures in the range from 50 to 120 ° C or by irradiating the mixture with ultraviolet rays. It is possible

if necessary, one or more additives such as an ultraviolet stabilizer, antioxidant, discoloration inhibitor, 55 fluorescent dye and the like. add to the mixture prior to its polymerization.

The lens manufacturing resin of the present invention thus obtained has a high refractive index, is very easy to process such as grinding, and has excellent heat, solvent and impact resistance. Accordingly, it can be used to manufacture eyeglass lenses, camera lenses and other optical lenses.

Some examples of the present invention are described in the following, wherein parts by weight and percentages by weight are given throughout. In addition, the following test methods were used to determine the resins according to the invention obtained in the examples

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to determine the refractive index, the ability to process by grinding, the resistance to heat, the resistance to impact and the resistance to solvents to manufacture lenses.

Refractive index: Measured at 20 ° C with an Abbe refractometer.

Processability: Each cast lens blank was ground using a grinding machine designed to manufacture spectacle lenses. Samples with polished surfaces were considered acceptable and are marked with a circle (o) in Table 1 below.

Resistance to heat: lens samples were left in a hot air dryer at 100 ° C for 2 hours and then removed from the dryer. Samples that showed neither discoloration nor surface deformation were considered acceptable and are marked with a circle (o) in Table 1 below.

Resistance to impact: A falling ball impact test was carried out in accordance with the FDA standards on flat plates with a thickness of 2 mm in the center. Unbroken samples were considered acceptable and are identified with a circle (o) in Table 1 below.

Resistance to solvents: lens samples were immersed in isopropanol, acetone and benzene at room temperature for 2 days and then removed. Samples that showed no change in surface area were considered acceptable and are identified with a circle (o) in Table 1 below.

Synthesis example 1

51.2 parts by weight of 4,4'-isopropylidenediphenol were dissolved in 250 parts by weight of chloroform and 68.0 parts by weight of triethylamine were then added. While cooling and stirring the resulting mixture in an ice bath, 79.6 parts by weight of allyl chloroformate was added dropwise to the mixture over 30 minutes. The temperature of the reaction mixture was then raised again to room temperature and stirring was continued for 2 hours. The liquid reaction product thus obtained was poured into a separation column and washed first with a saturated sodium hydrogen carbonate solution, then with water. The oily layer thus obtained was dried with Glauber's salt and then mixed with activated carbon with stirring. The mixture was filtered and the filtrate was concentrated to give 80.2 parts by weight of 4,4'-isopropylidendiphenylbisallyl carbonate as a colorless syrup (hereinafter referred to as component A).

Elemental analysis (% by weight):

Calculated for C23H2406: C = 69.68 H = 6.10

Found: C = 69.84 H = 5.97

NMRScocij: 1.64 (6H, S), 4.67 (4H, dd) 5.23 (2H, dd), 5.36 (2H, dd) 5.72-6.16 (2H, m), 6 , 96 ~ 7.20 (6H, m)

Synthesis example 2:

The synthetic procedure of Synthesis Example 1 was repeated, except that 82.1 parts by weight of 4,4'-isopropylidene-2,2 ', 6,6'-tetrachlorodiphenol instead of 51.2 parts by weight of 4, 4'-Isopropylidenediphenol were used so that a white solid was obtained. This was recrystallized from isopropanol to give 90.1 parts by weight of 4,4'-isopropylidene-2,2 ', 6,6'-tetrachlorodiphenylbisallyl carbonate (hereinafter referred to as component B) (melting point 109-111 ° C ).

Elemental analysis (% by weight):

Calculated for C23H20Cl4O6:

C = 51.71 H = 3.77 Cl = 26.55 Found:

C = 51.83 H = 3.49 Cl = 26.33

NMR§cdci3: 1.64 (6H, S), 4.76 (4H, dd) 5.30 (2H, dd), 5.41 (2H, dd) 5.76 ~ 6.22 (2H, m) , 7.40 (4H, S)

Synthesis example 3:

The synthesis procedure of Synthesis Example 1 was repeated, except that 122 parts by weight of 4,4'-isopropylidene-2,2 ', 6,6'-tetrabromodiphenol instead of 51.2 parts by weight of 4,4' -Isopropylidenediphenol were used so that a white solid was obtained. This was recrystallized from isopropanol to give 149 parts by weight of 4,4 / -isopropylidene-2,2 /, 6,6'-tetrabromaodiphenylbisallylcarbonate (hereinafter referred to as component C) (melting point 104-105 ° C.).

Elemental analysis (% by weight):

Calculated for C23H20Br4O6:

C = 38.80 H = 2.83 Br = 44.89 Found:

C = 38.76 H = 2.95 Br = 44.47

NMR5Cdci3: 1.63 (6H, S), 4.74 (4H, dd), 5.28 (2H, dd), 5.41 (2H, dd) 5.76-6.20 (2H, m), 7.32 (4H, S)

Synthesis example 4:

The synthesis procedure according to Synthesis Example 3 was repeated, except that 90.8 parts by weight of β-methallyl chloroformate was used instead of the 79.6 parts by weight of allyl chloroformate used in Synthesis Example 3, so that 154 parts by weight of 4, 4'-Isopropylidene-2,2 ', 6,6'-tetrabromodiphenylibis-ß-methallyl carbonate (hereinafter referred to as component D) to give (melting point 85-90 ° C).

Elemental analysis (% by weight):

Calculated for C25H24Br406:

C = 40.57 H = 3.27 Br = 43.19 Found:

C = 40.32 H = 3.51 Br = 43.00

NMR5CDa3: 1.63 (6H, S), 1.84 (6H, dd) 4.75 (4H, S), 5.30 (2H, d) 5.40 (2H, d), 7.32 (4H , S)

example 1

A liquid mixture obtained by heating a mixture of 50 parts by weight of component A from Synthesis Example 1 and 50 parts by weight of 2,4,6-tribromophenylallyl carbonate to 60 ° C was kept at 50 ° C , and 2 parts by weight of benzoyl peroxide were dissolved in the liquid mixture. The mixed solution thus obtained was poured into a mold which was formed from a glass mold and a gasket made of soft polyvinyl chloride and had been preheated to 50 ° C in advance. The mixed solution was kept in the mold at 60 ° C for 24 hours, at 80 ° C for 2 hours and at 100 ° C for 2 hours to carry out the copolymerization of the contents. The resin thus formed was then taken out of the mold and the refractive index, processing ability, heat resistance, impact resistance and solvent resistance were measured. As a result, it was found that the colorless transparent lenses thus obtained had a Bre5

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15

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35

40

45

50

55

60

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index of 1,595 and were excellent in grinding processing ability, heat resistance, impact resistance and solvent resistance.

Examples 2 to 10 In the same manner as in Example 1, monomers were copolymerized in various proportions to produce lenses. The results are shown in Table 1-5.

Table 1 Ex.

1

10th

Component of the polymer Component A

2,4,6-tribromophenylallyl carbonate

Component Ä

Allyl 3-bromobenzoate

Component B

Vinyl 2-chlorobenzoate

Component B

Allyl 2-chlorobenzoate

Component C

Vinyl benzoate

Component C

Vinyl 2-chlorobenzoate

Component C

Allyl 2-chlorobenzoate

Component D

Vinyl benzoate

Component D

Styrene

Component D phenyl methacrylate

(Weight, refraction, grinding

Parts) index availability

(40) 1.595 o (60)

(40) 1.588 o (60)

(40) 1.590 o (60)

(40) 1.591 o (60)

(50) 1.594 o (50)

(50) 1.604 o (50) '

(50) 1.602 o (50)

(50) 1,589 o (50)

(50) 1,597 o (50)

(60) 1.595 o (40)

therm. Wi-Schlagwi- sol. resistance resistance o o o o o o o o o o o o o o o o o o o o o

C.

i

Claims (2)

662 355 2nd PATENT CLAIMS 1. Copolymer resin with structural units of the general formula III 0 r-c-ch9oco 1 z ch „x ch, ococh2-c-r wherein X represents a hydrogen, chlorine or bromine atom and R represents a hydrogen atom or a methyl group, and with structural units of the general formula IV (III) -ch, (IV) wherein R 'represents a hydrogen atom or a methyl group and Y -0 -coch, -CH2OC-CO) I , q H where X 'is a chlorine or bromine atom, q is an integer from 0 to 5 and r is 0 or 1. 2. Lens made of plastic, characterized in that the plastic is a copolymer with structural units of the general formula III r-c-ch, oco- I 1 ch. V ococh, ch, I 2 -c-r in which X denotes a hydrogen, chlorine or bromine atom and R denotes a hydrogen atom or a methyl group, and with structural units of the general formula IV R '1 -c I. -ch, (IV) (III) 35 wherein R 'represents a hydrogen atom or a methyl group and Y -OC— (), -CH2OC-CO) r- (J, 0 0 where X 'is a chlorine or bromine atom, q is an integer from 0 to 5 and r is 0 or 1.